input[type=checkbox] {
    visibility: hidden;
}
.checkboxFour {
    width: 40px;
    height: 40px;
    background: #ddd;
    margin: 20px 20px;

    border-radius: 100%;
    position: relative;
    -webkit-box-shadow: 0px 1px 3px rgba(0,0,0,0.5);
    -moz-box-shadow: 0px 1px 3px rgba(0,0,0,0.5);
    box-shadow: 0px 1px 3px rgba(0,0,0,0.5);
}
.checkboxFour label {
    display: block;
    width: 30px;
    height: 30px;
    border-radius: 100px;

    -webkit-transition: all .5s ease;
    -moz-transition: all .5s ease;
    -o-transition: all .5s ease;
    -ms-transition: all .5s ease;
    transition: all .5s ease;
    cursor: pointer;
    position: absolute;
    top: 5px;
    left: 5px;
    z-index: 1;

    background: #333;

    -webkit-box-shadow:inset 0px 1px 3px rgba(0,0,0,0.5);
    -moz-box-shadow:inset 0px 1px 3px rgba(0,0,0,0.5);
    box-shadow:inset 0px 1px 3px rgba(0,0,0,0.5);
}
.checkboxFour input[type=checkbox]:checked + label {
    background: #26ca28;
}